# Copyright 2015, Tresys Technology, LLC
#
# This file is part of SETools.
#
# SETools is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation, either version 2.1 of
# the License, or (at your option) any later version.
#
# SETools is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with SETools.  If not, see
# <http://www.gnu.org/licenses/>.
#

import logging

from PyQt5.QtCore import Qt
from PyQt5.QtWidgets import QAction, QDialog, QFileDialog, QLineEdit, QMainWindow, QMenu, \
                            QMessageBox, QTreeWidgetItem, QVBoxLayout, QWidget
from setools import PermissionMap, SELinuxPolicy

from ..widget import SEToolsWidget
# Analysis tabs:
from .infoflow import InfoFlowAnalysisTab
from .terulequery import TERuleQueryTab


class ApolMainWindow(SEToolsWidget, QMainWindow):

    def __init__(self, filename):
        super(ApolMainWindow, self).__init__()
        self.log = logging.getLogger(self.__class__.__name__)

        if filename:
            self._policy = SELinuxPolicy(filename)
        else:
            self._policy = None

        try:
            # try to load default permission map
            self._permmap = PermissionMap()
        except (IOError, OSError) as ex:
            self.log.info("Failed to load default permission map: {0}".format(ex))
            self._permmap = None

        self.setupUi()

    def setupUi(self):
        self.load_ui("apol.ui")

        self.tab_counter = 0

        self.update_window_title()

        # set up error message dialog
        self.error_msg = QMessageBox(self)
        self.error_msg.setStandardButtons(QMessageBox.Ok)

        # set up tab name editor
        self.tab_editor = QLineEdit(self.AnalysisTabs)
        self.tab_editor.setWindowFlags(Qt.Popup)

        # configure tab bar context menu
        tabBar = self.AnalysisTabs.tabBar()
        self.rename_tab_action = QAction("&Rename active tab", tabBar)
        self.close_tab_action = QAction("&Close active tab", tabBar)
        tabBar.addAction(self.rename_tab_action)
        tabBar.addAction(self.close_tab_action)
        tabBar.setContextMenuPolicy(Qt.ActionsContextMenu)

        # connect signals
        self.open_policy.triggered.connect(self.select_policy)
        self.open_permmap.triggered.connect(self.select_permmap)
        self.new_analysis.triggered.connect(self.choose_analysis)
        self.AnalysisTabs.tabCloseRequested.connect(self.close_tab)
        self.AnalysisTabs.tabBarDoubleClicked.connect(self.tab_name_editor)
        self.tab_editor.editingFinished.connect(self.rename_tab)
        self.rename_tab_action.triggered.connect(self.rename_active_tab)
        self.close_tab_action.triggered.connect(self.close_active_tab)

        self.show()

    def update_window_title(self):
        if self._policy:
            self.setWindowTitle("{0} - apol".format(self._policy))
        else:
            self.setWindowTitle("apol")

    def select_policy(self):
        filename = QFileDialog.getOpenFileName(self, "Open policy file", ".")[0]
        if filename:
            try:
                self._policy = SELinuxPolicy(filename)
            except Exception as ex:
                self.error_msg.critical(self, "Policy loading error", str(ex))
            else:
                self.update_window_title()

                if self._permmap:
                    self._permmap.map_policy(self._policy)

    def select_permmap(self):
        filename = QFileDialog.getOpenFileName(self, "Open permission map file", ".")[0]
        if filename:
            try:
                self._permmap = PermissionMap(filename)
            except Exception as ex:
                self.error_msg.critical(self, "Permission map loading error", str(ex))
            else:

                if self._policy:
                    self._permmap.map_policy(self._policy)

    def choose_analysis(self):
        if not self._policy:
            self.error_msg.critical(self, "No open policy",
                                    "Cannot start a new analysis. Please open a policy first.")

            self.select_policy()

        if self._policy:
            # this check of self._policy is here in case someone
            # tries to start an analysis with no policy open, but then
            # cancels out of the policy file chooser or there is an
            # error opening the policy file.
            chooser = ChooseAnalysis(self)
            chooser.show()

    def create_new_analysis(self, tabtitle, tabclass):
        self.tab_counter += 1
        counted_name = "{0}: {1}".format(self.tab_counter, tabtitle)

        newtab = QWidget()
        newtab.setObjectName(counted_name)

        newanalysis = tabclass(newtab, self._policy, self._permmap)

        # create a vertical layout in the tab, place the analysis ui inside.
        tabLayout = QVBoxLayout()
        tabLayout.setContentsMargins(0, 0, 0, 0)
        tabLayout.addWidget(newanalysis)
        newtab.setLayout(tabLayout)

        index = self.AnalysisTabs.addTab(newtab, counted_name)
        self.AnalysisTabs.setTabToolTip(index, tabtitle)

    def tab_name_editor(self, index):
        if index >= 0:
            tab_area = self.AnalysisTabs.tabBar().tabRect(index)
            self.tab_editor.move(self.AnalysisTabs.mapToGlobal(tab_area.topLeft()))
            self.tab_editor.setText(self.AnalysisTabs.tabText(index))
            self.tab_editor.selectAll()
            self.tab_editor.show()
            self.tab_editor.setFocus()

    def close_active_tab(self):
        index = self.AnalysisTabs.currentIndex()
        if index >= 0:
            self.close_tab(index)

    def rename_active_tab(self):
        index = self.AnalysisTabs.currentIndex()
        if index >= 0:
            self.tab_name_editor(index)

    def close_tab(self, index):
        widget = self.AnalysisTabs.widget(index)
        widget.close()
        widget.deleteLater()
        self.AnalysisTabs.removeTab(index)

    def rename_tab(self):
        # this should never be negative since the editor is modal
        index = self.AnalysisTabs.currentIndex()

        self.tab_editor.hide()
        self.AnalysisTabs.setTabText(index, self.tab_editor.text())


class ChooseAnalysis(SEToolsWidget, QDialog):

    """
    Dialog for choosing a new analysis

    The below class attributes are used for populating
    the GUI contents and mapping them to the appropriate
    tab widget class for the analysis.

    The item_mapping attribute will be populated to
    map the tree list items to the analysis tab widgets.
    """
#    _components_map = {"Attributes (Type)": TERuleQueryTab,
#                       "Booleans": TERuleQueryTab,
#                       "Categories": TERuleQueryTab,
#                       "Common Permission Sets": TERuleQueryTab,
#                       "Object Classes": TERuleQueryTab,
#                       "Policy Capabilities": TERuleQueryTab,
#                       "Roles": TERuleQueryTab,
#                       "Types": TERuleQueryTab,
#                       "Users": TERuleQueryTab}
#
#    _rule_map = {"TE Rules": TERuleQueryTab,
#                 "RBAC Rules": TERuleQueryTab,
#                 "MLS Rules": TERuleQueryTab,
#                 "Constraints": TERuleQueryTab}
#
#    _analysis_map = {"Domain Transition Analysis": TERuleQueryTab,
#                     "Information Flow Analysis": TERuleQueryTab}
#
#    _labeling_map = {"fs_use Statements": TERuleQueryTab,
#                     "Genfscon Statements": TERuleQueryTab,
#                     "Initial SID Statements": TERuleQueryTab,
#                     "Netifcon Statements": TERuleQueryTab,
#                     "Nodecon Statements": TERuleQueryTab,
#                     "Portcon Statements": TERuleQueryTab}
#
#    _analysis_choices = {"Components": _components_map,
#                         "Rules": _rule_map,
#                         "Analysis": _analysis_map,
#                         "Labeling Statements": _labeling_map}

    _analysis_map = {"Information Flow Analysis": InfoFlowAnalysisTab}
    _rule_map = {"TE Rules": TERuleQueryTab}
    _analysis_choices = {"Rules": _rule_map,
                         "Analyses": _analysis_map}

    def __init__(self, parent):
        super(ChooseAnalysis, self).__init__(parent)
        self.item_mapping = {}
        self.parent = parent
        self.setupUi()

    def setupUi(self):
        self.load_ui("choose_analysis.ui")
        self.buttonBox.accepted.connect(self.ok_clicked)
        self.analysisTypes.doubleClicked.connect(self.ok_clicked)

        # populate the item list:
        self.analysisTypes.clear()
        for groupname, group in self._analysis_choices.items():
            groupitem = QTreeWidgetItem(self.analysisTypes)
            groupitem.setText(0, groupname)
            groupitem._tab_class = None
            for entryname, cls in group.items():
                item = QTreeWidgetItem(groupitem)
                item.setText(0, entryname)
                item._tab_class = cls
                groupitem.addChild(item)

        self.analysisTypes.expandAll()

    def ok_clicked(self):
        try:
            # .ui is set for single item selection.
            item = self.analysisTypes.selectedItems()[0]
            title = item.text(0)
            self.parent.create_new_analysis(title, item._tab_class)
        except (IndexError, TypeError):
            # IndexError: nothing is selected
            # TypeError: one of the group items was selected.
            pass
        else:
            self.accept()